1. Field of the Invention
The present invention relates to a surgical apparatus that can be inserted into an intracavital of a patient to thereby treat an affected area while observing the area using, for example, an endoscope.
2. Description of the Related Art
In recent surgical operations, a working space is secured by inserting a cylindrical sheath into an intracavital of a patient. The to-be-treated portion is observed by an endoscope inserted in the sheath. The to-be-treated portion or affected portion is treated by a surgical instrument inserted in a space between the endoscope and sheath. This technique is now widely used to reduce the invasiveness.
In the field of cerebral nerve surgery, endoscopic surgical operations using such a sheath have been recently demanded.
U.S. Pat. No. 6,142,931 has proposed, an example of an endoscopic surgical apparatus using a sheath. In this apparatus, an endoscope having an oblique-viewing angle of 30° or more with respect to the axis of its insertion section is provided in a sheath. The insertion section of the endoscope is arranged on the circumference of the sheath around the axis.
U.S. Pat. No. 5,697,939 discloses a holder apparatus. This apparatus fixes one point of the endoscope insertion section so that the insertion section can only rotate about the one point. This enables the field of view to be changed within an intracavital of a patient.